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United States Patent |
5,698,246
|
Villamar
|
December 16, 1997
|
Foodstuff for and method of feeding crustaceans and fish
Abstract
A liquid crustacean foodstuff comprising an encapsulated oil-coated
particulate feed in an aqueous media.
Inventors:
|
Villamar; Daniel F. (Maple Grove, MN)
|
Assignee:
|
Cargill, Incorporated (Minneapolis, MN)
|
Appl. No.:
|
592946 |
Filed:
|
January 29, 1996 |
Current U.S. Class: |
426/54; 426/2; 426/53; 426/623; 426/635 |
Intern'l Class: |
A23D 007/06 |
Field of Search: |
426/2,590,53,54,635,623
|
References Cited
U.S. Patent Documents
2800457 | Jul., 1957 | Green et al.
| |
3341416 | Sep., 1967 | Anderson et al. | 167/83.
|
3577515 | May., 1971 | Vandegaer | 424/32.
|
4087376 | May., 1978 | Foris et al. | 252/316.
|
4285720 | Aug., 1981 | Scher | 71/88.
|
4808417 | Feb., 1989 | Masuda | 426/2.
|
5401501 | Mar., 1995 | Pratt | 426/2.
|
Foreign Patent Documents |
616658 | Apr., 1990 | AU.
| |
237542 | Jan., 1991 | EP.
| |
0577034 | Jun., 1993 | EP.
| |
WO 87/01587 | Mar., 1987 | WO.
| |
WO 95/28830 | Nov., 1995 | WO.
| |
Other References
Encyclopedia of Polymer Science and Engineering, vol. 9, 2nd. Ed. (1987),
pp. 724-745.
Touraki et al., "Liposome Mediated Delivery of Water Soluble Antibiotics to
the Larvae of Aquatic Animals," Aquaculture 136 (1995) pp. 1-10.
Villamar et al., "Delivery of Dietary Components to Larval Shrimp (Penaeus
vannamei) by Means of Complex Microcapsules," Marine Biology 115 (1993)
pp. 635-542.
|
Primary Examiner: Paden; Carolyn
Attorney, Agent or Firm: Fitch, Even, Tabin & Flannery
Claims
What is claimed is:
1. A liquid crustacean foodstuff comprising:
an enrobed particulate crustacean foodstuff in a liquid media, the liquid
media comprising an antimicrobial,
the enrobed particulate crustacean foodstuff comprising a particulate
nutrient feed, an inner coating comprising an edible unsaturated oil
having a melting point of below about 29.degree. C. and an outer coating
comprising a gel which is complexed or crosslinked to an extent which is
effective to contain the oil-coated feed in an aqueous environment and
which is ingestible by the crustacean.
2. A liquid crustacean foodstuff as recited in claim 1, wherein the liquid
media includes an antimicrobial selected from the group consisting of
propylene glycol, glycerol, propionic acid, a water soluble salt of
propionic acid, sodium chloride, calcium chloride and mixtures thereof.
3. A liquid crustacean foodstuff as recited in claim 1, wherein the outer
coating comprises a crosslinked blend comprising alginate and protein.
4. A liquid crustacean foodstuff as recited in claim 3 wherein the
unsaturated edible oil is selected from the group consisting of fish oil,
cotton seed oil, peanut oil, soybean oil, sunflowerseed oil, palm oil,
coconut oil, rapeseed oil, corn oil, olive oil and mixtures thereof.
5. A liquid crustacean foodstuff as recited in claims 1 or 2 wherein the
outer coating comprises a crosslinked blend comprising alginate and
gelatin.
6. A liquid crustacean foodstuff as recited in claim 4, wherein the
nutrient feed comprises a particulate feed and endo-probiotic bacteria.
7. A liquid crustacean foodstuff as recited in claim 1 wherein the
unsaturated edible oil is selected from the group consisting of fish oil,
cotton seed oil, peanut oil, soybean oil, sunflowerseed oil, palm oil,
coconut oil, rapeseed oil, corn oil, olive oil and mixtures thereof.
8. A liquid crustacean foodstuff comprising:
an enrobed particulate crustacean foodstuff in an aqueous liquid media, the
liquid media comprising an antimicrobial selected from the group
consisting of propylene glycol, glycerol, propionic acid, a water soluble
salt of propionic acid, sodium chloride, calcium chloride and mixtures
thereof, and ecto-probiotic bacteria.
the enrobed particulate crustacean foodstuff comprising a nutrient feed
which comprises a particulate feed and endo-probiotic bacteria, the
nutrient feed having an inner coating comprising an edible unsaturated oil
having a melting point of above about 29.degree. C. and an iodine value of
at least about 85 and an outer coating comprising a crosslinked
alginate/protein gel.
9. A liquid crustacean foodstuff as recited in claim 8, wherein the outer
coating is a crosslinked alginate gelatin gel.
10. A liquid crustacean foodstuff as recited in claim 8, wherein the
aqueous liquid media comprises a blend of a liquid antimicrobial selected
from the group consisting of propylene glycol, glycerol, propionic acid
and mixtures thereof and an antimicrobial water soluble salt in an amount
effective for stabilizing the liquid foodstuff.
11. A liquid crustacean foodstuff as recited in claim 10, wherein the water
soluble salt is calcium chloride.
12. A liquid crustacean foodstuff as recited in claims 8, 9 or 10, wherein
the foodstuff includes from about 0.1 to about 5.0 weight percent
endo-probiotic, based upon the weight of the particulate feed.
13. A liquid crustacean foodstuff as recited in claims 8, 9 or 10, wherein
the aqueous liquid medium further includes from about 6 to about 12 weight
percent, based upon the weight of the liquid foodstuff, ecto-probiotic.
14. A liquid crustacean foodstuff comprising:
an enrobed particulate crustacean foodstuff in an aqueous liquid medium,
the enrobed particulate foodstuff comprising a particulate feed having a
particle size in the range of from about 2 to about 100 microns, from
about 15 to about 30 weight percent, based upon the weight of the
particulate feed, edible unsaturated oil and from about 0.1 to about 5.0
weight percent, based upon the weight of the particulate feed,
endo-probiotic bacteria, the liquid media comprising water, an
antimicrobial water soluble salt and a liquid antimicrobial selected from
the group consisting of propylene glycol, glycerol, propionic acid and
mixtures thereof, and an ecto-probiotic bacteria,
the enrobed particulate crustacean foodstuff having an inner coating and
outer coating, the edible unsaturated oil forming the inner coating on and
into the surface of the particulate feed, the oil having a melting point
of below about 29.degree. C. and an iodine value of at least about 85, the
outer coating comprising a blend of alginate and gelatin which has been
gelled and crosslinked.
15. A method for time releasing feed to crustaceans and fish, the method
comprising:
adding a liquid foodstuff of claim 14 to an aquatic environment which
includes the crustaceans, the liquid foodstuff being added in an amount
effective for feeding the crustaceans, but in and amount such that after
24 hours not more than about 0.01 grams of nitrogen per gram of liquid
foodstuff is converted to nitrogen in ammonia.
16. A method for making a liquid foodstuff for crustaceans and fish, the
method comprising:
enrobing a particulate feed and a endo-probiotic bacteria with an edible
unsaturated oil having a melting point of above about 29.degree. C. and an
iodine value of at least about 85 to provide an oil-coated nutrient feed;
embedding the oil-coated nutrient feed in an alginate and gelatin gel;
crosslinking the gel to provide an microencapsulated oil-coated feed;
sieve separating the microcapsules containing the oil-coated feed to
provide microcapsules with a diameter of from about 50 to about 1000
microns; and
blending the microcapsules into an aqueous liquid media comprising water,
an antimicrobial water soluble salt and a liquid antimicrobial selected
from the group consisting of propylene glycol, glycerol propionic acid and
mixtures thereof, and a ecto-probiotic bacteria.
Description
BACKGROUND OF THE INVENTION AND DESCRIPTION OF THE PRIOR ART
Aquaculture has become an increasingly significant contributor to the
world's seafood supply. Aquaculture operations occur worldwide with a
large concentration of such operations occurring in Asia. Typical
aquaculture operations take place in contained ponds which are seeded with
crustaceans, fish or shellfish. Seed stock is supplied to sophisticated
aquafarms by aquaculture systems in which the environment of the contained
pond is artificially controlled to provide optimum growth conditions. An
increasing demand for seafood products and limits on the amount of seed
stock available in nature has created the need for increased production
efficiencies in crustacean, shellfish and finfish hatchery and nursery
facilities. A critical factor effecting these aquaculture operations is
the feeding process.
Conventional aquatic larval feeds are provided in a dry form as a powdered
or flaked feed. They generally are poor supplements to live-food organisms
fed to hatchery and nursery seed stock. Dry feeds are either added
directly to an aquaculture system or mixed with water prior to use.
Conventional dry feeds rapidly deteriorate in tank water, with physical
decomposition and breakdown of the dry feed starting immediately with wet
mixing. The large immediate decomposition that takes place when preparing
and using dry feeds results in a significant contamination of culture tank
water. With commercial feeding programs that depend on dry and prepared
feeds such as flakes, powders and egg custards, the concentration of
decomposing organic matter in culture tank water increases as feeding
rates increase resulting in high levels of toxic ammonia and other
pollutants. The resulting unhealthy water conditions contribute to the
proliferation of pathogens including protozoan fouling organisms such as
Zoothanmium, thus reducing the overall productivity of the tank.
Stages in the life cycle of certain aquatic organisms, such as shrimp,
require critical attention and care in the feeding process. Feeding
programs using dry feeds are difficult to automate, require expensive
labor intensive practices, and are prone to feeding errors which affect
the overall productivity of the system. Further, with the use of dry
feeds, significant amounts of nutrients are lost to the water and dry
feeds are typically of a size that makes nutrients unavailable to certain
aquatic organisms at specific times in their life cycles.
One approach to overcoming some of the disadvantages associated with dry
feeds has been the development of micro-encapsulated diets. EP 237542
describes a system where a nutritional component is entrapped in a
liposome and the liposome is further encapsulated in a hydrocolloid
matrix. The resulting lipogel microcapsules were either stored as a
freeze-dried powder or suspended in water containing chloramphenicol.
Further, Villamar et al. (Marine Biology, 115:635 (1993)) describes the
preparation of complex microcapsules (CXMs) consisting of dietary
ingredients and lipid-wall microcapsules (LWMs) embedded in particles of a
gelled mixture of alginate and gelatin to obtain a single food-particle
type used to provide suspension feeders with dietary nutrients. CXMs were
lyophilized and stored under nitrogen at -20.degree. C.
It also has been suggested in WO 87/01587 that microcapsules using
liposomes are useful to time deliver materials such as medications. These
types of microcapsules, however, are based upon phospholipids which form a
membrane around the medication which is subject to time release. This type
of membrane or barrier is fragile, potentially expensive and difficult to
make and would not likely remain a discrete microcapsule when combined
with other materials which would desirably form an appropriate part of a
feed for marine animals. Moreover, liposomes are capable of providing only
low levels of feed for each liposome.
The micro-encapsulated feeds described in the art do not solve all of the
problems associated with dry feeds. Production of nutrient in liposomes
and their subsequent encapsulation in a hydrocolloid matrix is a labor
intensive process which adds to the cost of the final feed. Freeze drying
of micro-encapsulated feeds results in oxidation of the lipid component,
providing a less desirable feed. Micro-encapsulated feeds that are stored
in a lyophilized state still have some of the same disadvantages as
described for dry feeds, as the lyophilized feed must still be rehydrated
and manually introduced into a tank. Further, the micro-encapsulated feeds
described in the prior art have not eliminated the water pollution
problems associated with the use of dry feeds.
SUMMARY OF THE INVENTION
The invention provides a liquid foodstuff composition, a method for making
a liquid foodstuff and a method for feeding crustaceans, such as larval
and post larval shrimp, and fish. The liquid foodstuff includes a
particulate feed in a liquid medium and provides an easy convenient way to
deliver a nutritionally formulated ration to crustaceans and fish. The
liquid foodstuff of the invention includes oil-coated nutrient feed
particles which are embedded in a gel or a food in a polymer blend. The
gel is crosslinked or complexed to encapsulate the oil-coated nutrient to
provide encapsulated oil-coated nutrient feed. To further maintain the
marine environment and stabilize the encapsulated oil-coated nutrient feed
particles without drying or freeze drying them, the encapsulated
oil-coated feed is dispersed and stabilized in a liquid medium for
delivery to marine animals.
The oil-coated nutrient feed includes particulate feed, endo-probiotic
bacteria and oil in and on the surface of the feed. The endo-probiotic
bacteria aids the digestion of the marine animal. The edible oil has a
melting point below about 29.degree. C. Typical oils include fish oil,
peanut oil, olive oil, corn oil, coconut oil, sunflowerseed oil, cotton
seed oil, soybean oil, rapeseed oil and palm oil. The feed is mixed with
the oil and the oil forms an inner coating for the particulate feed. The
oil in liquid form is intimately mixed with the feed such that the feed is
encoated with the oil and the oil is at least on and/or into the surface
of the feed. In some cases the oil is substantially homogeneously
dispersed throughout the feed particles. This is in contrast to
microcapsules formed by liposomes lying as a fragile membrane over the
surface of the feed. These liposome microcapsules can be fractured or
destroyed in further processing or in a hostile aquatic environment. This
destruction can release the contents inside the liposome, which in the
case of a marine feed, would contaminate the marine environment.
The oil-coated nutrient feed is enrobed or encapsulated in an outer coating
which is a crosslinked gelled matrix to provide a microcapsule foodstuff.
In an important aspect, the gel provides a hydrocolloid matrix, and in a
particularly important aspect, the hydrocolloid matrix is a gelled blend
of alginate and gelatin which blend is crosslinked to encapsulate the
oil-coated nutrient. The microcapsules have a size range of from about 50
to about 1000 microns. This encapsulation prevents nutrient from being
leached from or moving from the oil-coated nutrient feed into the aqueous
environment of the marine animal. Nutrients leached into the aqueous
marine environment if not eaten by marine animals, will decompose and
contaminate that environment. Such contamination results in increased
levels of toxic ammonia and other pollutants.
The liquid medium into which the encapsulated foodstuff is dispersed
comprises water and an antimicrobial composition. In an important aspect
the antimicrobial is a liquid antimicrobial such as propylene glycol or
glycerol. Propionic acid also can be used as a liquid antimicrobial or the
salt thereof may be added into the aqueous liquid medium. In a
particularly important aspect, the liquid antimicrobial composition is
combined with a water soluble antimicrobial salt such as calcium chloride.
In another aspect of the invention, the liquid medium also includes
ecto-probiotic bacteria. This bacteria grows in the aquatic environment
into which the liquid foodstuff is added. The ecto-probiotic metabolizes
waste and helps maintain a clean water environment for marine life.
With use of the liquid foodstuff of the invention, not more than about 0.01
grams of nitrogen per gram of liquid feed is converted to nitrogen in
ammonia after 24 hours in natural seawater.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The foodstuff of the invention is made by preparing an oil-coated nutrient
feed by mixing a particulate or powdered feed having a particle size in
the range of from about 2 .mu.m to about 100 .mu.m, oil and endo-probiotic
bacteria. The oil-coated nutrient feed includes the powdered feed, from
about 15 to about 30 weight percent, based on the weight of the feed, oil,
and from about 0.1 to about 5.0 weight percent, based upon the weight of
the feed, endo-probiotic bacteria. Preferably the nutrient feed also
includes from about 3 to about 5 weight percent, based upon the weight of
the feed, emulsifier and from about 0.02 to about 0.04 weight percent,
based upon the weight of the feed, antioxidant. Emulsifiers such as
Santone and lecithin may be used. Rendox is a commercially available
antioxidant which may be used. The feed and dry ingredients are blended
before they are mixed with the oil. The oil serves to make the feed
hydrophobic and is on and in the feed. Endo-probiotics which may be used
in the product of the invention include dried B. licheniformis and B.
subtilis strains commercially available from Cris Hansen's Biosystems.
The particulate feed may be adjusted for the requirements of the marine
animal being fed as is known. For shrimp, the feed comprises animal
protein, brine shrimp, egg product, betaine, alanine, isoleucine, leucine,
serine, valine, glycine, astaxanthin, vitamin A supplement, vitamin B 12
supplement, riboflavin supplement, calcium pantothenate, niacin
supplement, vitamin D 3 supplement, vitamin E supplement, menadione sodium
bisulfite complex, folic acid, biotin, thiamine, pyridoxine hydrochloride,
inositol and choline chloride. The particulate feed may also include
medicaments. In one important aspect, edible oil has an IV value of at
least about 85 and a melting point below about 29.degree. C. Typical oils
include fish oil, peanut oil, olive oil, corn oil, sunflowerseed oil,
cotton seed oil, soybean oil and rapeseed oil. In an alternative aspect of
the invention, oils having an IV lower than about 85 may be used, for
example coconut oil and palm oil. Heating of the oils or particulate feed
may be used to maintain the oils in a liquid state for uniform coverage.
In an important aspect of the invention, the oil provides the Omega-3 HUFA
(highly unsaturated fatty acid) dietary requirements of marine shrimp and
fish by providing EPA (eicosapentaenoic acid) and DHA (docosahexenoic
acid).
A food in gel blend is made by embedding the oil-coated nutrient feed into
a gel which when crosslinked or complexed to encapsulate the oil-coated
feed is effective to contain the oil-coated nutrient feed in an aqueous
environment. The food in gel blend comprises from about 30 to about 40
weight percent oil-coated nutrient feed and from about 70 to about 60
weight percent gel. Preferably the food in gel blend will comprise from
about 38 to about 40 weight percent oil-coated nutrient feed. The gel may
be made from a complex coacervate of components, organic polymers, gums
such as acacia (gum arabic) and carrageenan, sugar, such as maltodextrins
and sucrose, ethyl cellulose, wax, fat or protein. The gel is complexed or
crosslinked to provide hydrophobic properties to the oil-coated feed and
must be ingestible by the marine animal. Microcapsules formed have a
particle size of from about 50 to about 1000 microns. A "complexed
coacervate" means an aggregate of colloidal droplets held together by
electrostatic attractive forces. It is a mixture of polyelectrolytes which
have an appropriate ionic charge and molecular chain lengths to
encapsulate the oil-coated feed. The gel also may be a protein which upon
crosslinking through in situ or interfacial polymerization will
encapsulate the oil-coated feed. The protein also may be denatured to
encapsulate the oil-coated food or may be made into microspheres to
encapsulate the feed by solvent evaporation.
In an important aspect of the invention, the hydrocolloid gel comprises a
gelled blend of alginate, such as sodium alginate and polypeptides or
proteins such as gelatin. The alginate and gelatin blend are gelled in
water. The ratio of alginate to gelatin is from about 5:1 to about 2.75:1.
The protein or polypeptide provides cites opened by proteases which allows
the marine animal to digest the feed. Crustaceans, such as shrimp, are
capable of masticating the outer coating, such as the crosslinked
alginate/gelatin blend, are benefitted by the protein in the outer coating
and almost immediately are capable of consuming the oil-coated nutrient.
The gel also may include a water soluble hexametaphosphate such as sodium
hexametaphosphate, the alginate/gelatin/hexametaphosphate blend having a
ratio in the range of from about 5:1:1 to about 2.75:1:0.5.
Processes known in the art that may be adapted for use in encapsulating the
oil-coated nutrient feed include complex coacervation (U.S. Pat. No.
2,800,457), polymer-polymer incompatibility (U.S. Pat. No. 3,341,416),
interfacial and in situ polymerization (Wittbecker et al., J. Polym. Sci.
40:299 (1959); U.S. Pat. Nos. 3,577,515, 4,285,720, and 4,087,376),
fluidized-bed and Wurster processes (Hall et al. Controlled Release
Technologies: Methods, Theory and Applications, Vol. II, CRC Press, Inc.
Boca Raton, Fla. (1980)), desolvation, solvent evaporation from emulsions,
gelation, pressure extrusion, spray drying and congealing, coextrusion,
vacuum coating, and electrostatic deposition, which are further described
in Encyclopedia of Polymer Science and Engineering, Vol. 9, 2nd Ed.
(1987).
In the aspect of the invention where the gel is the alginate/gelatin blend,
the food in gel blend is made by blending the oil-coated nutrient feed
with the alginate/gelatin blend and deionized water. This provides an
aqueous blend which includes the hydrocolloid gel. The pH of the aqueous
blend is adjusted to about 12. The oil-coated nutrient feed is
encapsulated in the alginate/gelatin matrix by ionically cross linking the
gelatin and alginate. This is done by atomizing the food in polymer blend
into an aqueous solution of multivalent ion such as from about 5 to about
25 weight percent calcium chloride. This crosslinking reaction provides
microcapsules of oil-coated nutrient feed where the oil forms an inner
coating and the crosslinked gel forms an outer coating for the nutrient
feed.
The resulting microcapsules of oil-coated nutrient feed are sieve separated
into desired size, such as from about 50 to about 1000 microns. The
capsules are not required to be dried or freeze dried to avoid bacterial
degradation and spoilage.
In another aspect of the invention, the food in polymer blend is sprayed
into an aqueous solution of multivalent ion, such as calcium chloride, to
provide an elongated bead or worm-like product. A process similar to that
used to provide microcapsules is utilized with adjustment of pressure and
spray rates, such that a worm-like product forms. The worm-like product is
desirably about 0.5 to about 5.0 mm wide and about 1 to about 50 mm long.
The product may be used as a food for juvenile and adult crustaceans and
fish as food for the maturation/reproduction phase of aquaculture field,
such as broodstock nutrition.
The liquid foodstuff is provided by blending the microcapsules into water
which includes an antimicrobial. In an important aspect, the aqueous blend
includes a liquid microbial such as propylene glycol and/or glycerol. The
antimicrobial also may include propionic acid or salt thereof in the
aqueous blend. In a particularly important aspect of the invention, the
aqueous blend includes the liquid antimicrobial and a water soluble
antimicrobial salt, such as calcium chloride and sodium chloride. The
water soluble antimicrobial salt will increase the specific gravity of the
aqueous liquid medium for the microcapsules such that the suspending power
of the liquid medium is increased. To further increase the suspending
power of the aqueous liquid medium or blend, the liquid antimicrobial is
sufficiently viscous such that when the liquid antimicrobial,
antimicrobial water soluble salt, and water are blended each will be in
amounts effective to stabilize the microcapsules in the aqueous
antimicrobial blend for at least about 60 minutes. Product is packaged and
sealed under nitrogen to provide shelf stability of at least about 6
months at about 25.degree. C. to about 30.degree. C.
Further the aqueous liquid medium of the liquid foodstuff also includes
ecto-probiotic bacteria such as Bacillus sp. spores. In one aspect of the
invention, the ecto-probiotic comprises about equal amounts of Bacillus
licheniformis (sold commercially as HB-2 by AMS, Shakepee, Minn.) and
Bacillus subtilis (sold commercially as AB-1 by AMS, Shakepee, Minn.).
While not intending to be bound by any theory, it is thought that the
Bacillus licheniformis, which is isolated from topsoil, produces large
quantities of proteolytic enzymes that attack proteins in decaying organic
matter, thus reducing foam on the pond surface and improving water
transparency. Bacillus licheniformis appears to repopulate the slime layer
and compete with pathogenic bacteria that could take over the slime layer
and cause disease.
The composition of the invention includes the various component as set
forth below.
______________________________________
Encapsulated Feed from about 30 to about 40
Capsules weight % of final product
Food in Gel % from about 30 to about 40
weight % of final product
Feed % from about 9 to about 16%
of final product
______________________________________
Component % of Feed % of Final Product
______________________________________
Endo-probiotic
0.1-5.0%
0.01-1.0
(in encapsulated
feed)
Ecto-probiotic
-- 6-12
(in liquid)
Propylene Glycol
-- 15-25,
(preferably 19%)
Antimicrobial Salt
-- 20-30
(CaCl.sub.2, NaCl)
Feed 100 9-16
Fish Oil 15-30 1.5-5.0
Emulsifiers
"Santone" 1-2 0.1-0.5
Lecithin 1.8-3.0 0.16-0.48
Antioxidant 0.02-0.04 20-65 ppm
"Rendox"
______________________________________
The following examples set forth exemplary compositions of the invention
and how to practice the method of the invention.
EXAMPLE 1
Preparation of Liquid Feed
A mixture of fine powder nutrient feedstuffs containing 1% probiotic
bacteria and formulated to provide complete nutrition for larval and
postlarval shrimp and fish is mixed with a warm mixture of fish oil,
emulsifying agent and antioxidant. The oil used to mix with the feedstuffs
has the following specifications.
______________________________________
Free Fatty Acid
0.50% max. Color, Gardner 8 max.
Iodine Value
175-200 Cold Test in Hours 2 min.
Moisture and Imp.
0.50% max. Peroxide Value, MEQ/KG 10
max.
______________________________________
Typical Fatty Acid Composition
% By Weight
______________________________________
C14:0 6.85 C20:0 0.17
C15:0 0.46 C20:1 1.48
C16:0 14.83 C20:2 0.18
C16:1 9.74 C20:3 0.37
C16:2 1.62 C20:4 2.09
C16:3 1.51 C20:5 14.16
C16:4 1.53 C21:5 0.76
C17:0 0.38 C22:0 0.10
C18:0 2.55 C22:1 0.33
C18:1 9.58 C22:4 0.24
C18:2 1.93 C22:5 2.82
C18:3 1.48 C22:6 10.26
C18:4 3.09 C24:0 0.60
C19:0 0.00 C24:1 0.22
______________________________________
The oil used had the following characteristics.
______________________________________
Color (Gardner) 7.00
Cold Test @32 F. 3.5 hours
Iodine Value 187
Free Fatty Acids 0.12%
Moisture 0.11%
Peroxide Value 2.0
______________________________________
The lipid coated powder mixture is blended at 40% (w/w) into a warm sodium
alginate (2.75% w/w) and gelatin (0.5% w/w) polymer in deionized water
adjusted to pH 12.
The resultant 40% food-in-gel blend is atomized into a batch of chilled 20%
(w/w) calcium chloride solution by pumping through an external mix spray
nozzle assembly supplied with nitrogen gas at 40-120 psi. Upon contacting
the calcium chloride solution, the atomized droplets become ionically
crosslinked by reaction of calcium atoms with the sodium alginate matrix
forming calcium-alginate microcapsules.
The microcapsules are sieve separated into desired sizes ranging from <50
microns to >1000 micron equivalent spherical diameter. These capsules are
stabilized in liquid preservative composed of propylene glycol, calcium
chloride and an additional probiotic bacteria.
EXAMPLE 2
Comparison of Nitrogen Release from Dry and Liquid Feeds
A total of 25, 2-ton, culture tanks containing seawater were divided into
five control tanks (dry feed), and five tanks consisting of four different
feeding densities of liquid feed as prepared in Example 1.
A standard feeding program used at the Thai Department of Fisheries
research station was used in the control tank. Liquid feed was used to
completely replace commercial dry feeds and partly or completely replace
Artemia nauplii use in the control tanks. Microalgae was the same for all
tanks. Shrimp larvae (nauplius stage) were stocked at 200,000 per tank on
Day-0. Sample of tank water were removed with time and analyzed for
nitrogen content and for the occurrence of Zoothanmium.
Zoothanmium observations through the PL-2 stage showed that 5 of 5 control
tanks had zoothanmium infestation, whereas 0 of 20 tanks containing the
liquid feed had zoothanmium infestation. Further, shrimp larvae in tanks
containing the liquid feed metamorphosed to the PL-1 stage about 1 day
sooner than shrimp in the control tanks (dry feed).
Results of ammonia nitrogen analysis were as follows.
______________________________________
AMMONIA-N
(mg/L)
Day A B C D E
______________________________________
1 0.0075 0.0019 0.0030 0.0039
0.0036
3 0.1105 0.0254 0.0105 0.0095
0.0227
6 0.3918 0.0144 0.0163 0.01273
0.0174
9 0.6689 0 0 0 0
13 0.7517 0 0 0 0
16 0.2529 0.0349 0.0192 0.0243
0.0152
20 1.2934 0 0.0004 0.0042
0.0004
______________________________________
A: Control (dry feed)
B-E: Liquid Feed
Nitrogen is expressed as a mean value in mg of ammonia nitrogen per liter
of tank water.
EXAMPLE 3
Feeding of Shrimp
______________________________________
Penaeus monodon Zoea-1 through PL1 are stocked at 100,000 larvae
per ton of seawater. The daily ration is divided into 5-6 feedings per
tank per day according to the following.
Liquid Feed
Liquid Feed
Stages Z-M
Stages M-PL
Microalgae
(cc/Ton (cc/Ton (cells/ul
Brine Shrimp
Stage SW/day) SW/day) SW/day) (g cyst*/ton/day)
______________________________________
N -- -- 100 --
Z1 20 -- 100 --
Z2 25 -- 100 --
Z3 30 -- 100 --
M1 45 -- 40 --
M2 40 20 40 --
M3 15 30 40 --
PL1 5 45 20 --
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Feeding can be adjusted as needed to fit specific hatchery/nursery
management practices (i.e., cc/for SW/day).
*Newly hatched brine shrimp (Artemia) nauplii recovered from 5-10 g cyst
cc = cubic centimeter = 1 ml
SW = seawater
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